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WSU/Pend Oreille Extension introduced the Sense of Place series in 1999, with a focus on local landscape and natural history of Pend Oreille County, Washington. A partnership with the Kalispel Tribe of Indians Natural Resources Department has allowed us to expand this program through EPA funding to include more classes, a newsletter and this website.

Chronicles of Sub-Nivea

by John Stuart

When winter comes knocking at the door, we say the growing season is “over” and that many life forms are “dormant”. But nature’s obligatory activities can’t really come to a stop in winter. In cold weather, many small life forms, especially insects and some rodents take a six month break from the whole shebang. But for others, like ourselves, a warmer coat and gloves or the equivalent are doffed and life goes on. With an active growing season just ended, all the recently-used-to-be green plant matter that has just been shed by both deciduous and conifer plants is lying on the ground and begging for action. Because it is wrapped in a warmish coat of snow with old Mom Earth generating heat from below, the narrow little elf quarters between earth and snow become an icy maze of winter activity.

Where the ground is covered with grass, brush or the beneficial litter and deadwood of a forest, the snow does not plaster itself to the dirt. Instead, it is held slightly off the surface, and a highly irregular maze of tunnels form. This labyrinth is used by many 4-6-8 and 100 -legged creatures. The scientist calls this narrow layer (usually 3-5 cm. from top to bottom) the sub-nivean space. The intellectuals out there will quickly figure out that niveus (Latin) means snow. The Inuit, experts on snow long before Latin came along, call the crystalline network pukak.

With as little as one foot of snow on the ground and surface temperatures as low as –50 F, the pukak temperature can be as high as +20 F. With deeper snows, and milder temperatures here in Pend Oreille country, the sub-nivean space can be just below freezing or even slightly above. Very mild indeed.

Let’s get back to all that dead stuff. Because the ground surface is covered with lots of dead matter, and few green plants, the sub-nivean space has a high population of, fancy word again, detritivores, or things that eat all that dead stuff. Springtails and mites are two of the most numerous general life forms. Earthworms are also present. There are many species within these larger groups. Because fungi are involved in breaking down much of this plant matter, some springtail and mite species are present as fungus eaters, or fungivores. With numerous detritivores present, it is obvious that there will also be, in the pukak, predators on these creatures as well. These include spiders, beetles, ants, wasps and centipedes.

Invertebrates that can run around without long-handles in below freezing temperatures have other ways of coping. One of the more common strategies is to have up to 35 % of their body weight consist of different alcohols, including glycerol, good old anti-freeze.

The insects and spiders have to have their predators as well, so we find shrews and voles as the predominant rodents able to move through the space with the low ceiling. Shrews, in particular, are avid insect eaters. With the sub-nivean space being connected to larger below snow spaces, the bigger fuzzy ones can take advantage of what is going on underneath the snow. In a healthy forest, large amounts of dead wood, snags, old root wads and snow laden green saplings will form a variety of bare-ground spots and access routes into the pukak and into the cavities in the dead wood itself. These become great winter retreats for squirrels, weasels, marten, snowshoe hare, grouse. The larger meat-eaters like weasels, marten, coyote and bobcat depend on the small rodents and herbivores. Therefore, bountiful supplies of logs and branches invite a wide variety of creatures into the winter land of Sub-Nivea.

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